Food delivery containers, such as hot bags for pizza, are commonly used to keep food from getting cold during transportation. Typically, these containers are lightweight, durable, portable, and generally use insulation, a temperature control source, or both in combination.
Hot bags have developed over time from simple insulated containers to actively heated containers. An insulated container simply minimizes heat loss. A heated container uses a heat source to add heat to a food item, instead of simply retarding heat loss. Heated containers may keep food items warmer for a longer time period so that a delivery person may have more time to deliver the food and a warmer product may be provided to the consumer. Heated containers can also be used for in-store heated storage of food items.
In many heated containers, the heat source is placed with the food item inside the food storage compartment. Since these containers are used frequently, the constant loading and unloading of food items call cause damage to the bag and the heat source itself. Pizza boxes, for example, can easily snag or impact a heat source, causing damage to the heat source, the pizza box, or both. Direct contact also creates a heat distribution issue. With many configurations, the heat source will provide uneven heat, causing hot and cold spots.